From: Andrew Jones <drjo...@redhat.com>
Fix a QEMU NULL derefence that occurs when the guest attempts to
enable PMU counters with a non-v8 cpu model or a v8 cpu model
which has not configured a PMU.
Fixes: 4e7beb0cc0f3 ("target/arm: Add a timer to predict PMU counter overflow")
Signed-off-by: Andrew Jones <drjo...@redhat.com>
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Message-id: 20190322162333.17159-2-drjo...@redhat.com
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
---
target/arm/helper.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index c8d3c213b6b..fc73488f6cc 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1259,6 +1259,10 @@ static bool pmu_counter_enabled(CPUARMState *env,
uint8_t counter)
int el = arm_current_el(env);
uint8_t hpmn = env->cp15.mdcr_el2 & MDCR_HPMN;
+ if (!arm_feature(env, ARM_FEATURE_PMU)) {
+ return false;
+ }
+
if (!arm_feature(env, ARM_FEATURE_EL2) ||
(counter < hpmn || counter == 31)) {
e = env->cp15.c9_pmcr & PMCRE;
--
2.20.1
